Obesity is a problem prevailing around the world for decades now and it has been steadily increasing in intensity and severity. Dietary habits may have a direct or indirect impact on imbalance in Body Mass Index (BMI) and hence on the prediction of obesity among teenagers.  This research will review literature on the reasons of obesity and impact of dietary habits on obesity among teenagers. The study will also try to find if any gender based differences exist in impact of dietary habits on obesity among teens.

Obesity Prevalence Maps

Obesity prevalence has been increasing steadily around the world. Janssen et al, (2005) evidenced a high increasing rate of obesity among children and adolescents from 1980s to 1990s and informed that this increasing trend has continued into the 21st century. An analysis of 2001-2002 self-reported data of 137, 593 youth between the ages of 10 – 16 years from 34 countries which included a majority of European countries, revealed that United States ranked 2nd to highest after Malta in obesity and pre-obesity rates. According to Center for Disease Control and Prevention (2015), obesity estimates of 2014 show that no state in America had obesity rates below 20%, 5 states and District of Columbia had the minimum obesity rates ranging (20-25%), 42 states ranged 25-35% in obesity rates while Arkansas, Mississippi and West Virginia showed the 35% and above obesity rates. Rodrigo (2013) concluded on secondary data from 199 countries that Body Mass Index (BMI) for men increased in every sub-region except Central Africa and South Asia from 1980 to 2008. Where higher BMI is an indicator leading to obesity. Highest increase in male BMI among high income countries was in USA.

Problems and Consequences of Obesity

Obesity is a severe health problem. Obesity has been found to be associated with several health problems. According to Rodrigo (2013) high Body Mass Index (BMI) has been qualified as being associated with various diseases around the world. The source stated obesity to be a major factor in causing non-communicable diseases like Diabetes, Cardio-vascular diseases and cancer. World Health Organization (as cited in Rodrigo, 2013) listed obesity among the leading global mortality risks in the world, where overweight and obesity have been stated to contribute for 5% of deaths around the globe. WHO also listed obesity among eight high risk factors which cause 61% of Cardio-vascular deaths and more than 75% of ischemic heart diseases (Rodrigo, 2013).

Reasons behind obesity

A volume of research has been carried out over time to shortlist reasons contributing to obesity among different age groups. Farajian et al, (2014) investigated the dietary and physical activity habits and behaviors of children in order to establish findings about the reason behind overweight and obesity among children. The research concluded breakfast frequency, daily number of meals and snacks, frequency of family meals, use of TV/PC/Video game player in the bed room, study hours, mothers’ age, and parental BMI to be the most important predictors of overweight and obesity among children. Garaulet et al (2011) investigated 3311 adolescents from 10 European cities to find the reasons for increasing obesity among adolescent. The study found that shorter sleep duration is associated with increasing obesity. The study also found that dietary habits can direct sleep durations and hence obesity.

Purpose of this Study

The purpose of this current research study is to investigate the available literature to establish relationship between dietary habits and prevalence of obesity among teenagers aged 12-18 years. The primary question to investigate in this research review will be whether any direct or indirect relationship exists between dietary habits and obesity among teenage groups (12-18 years). Secondary questions can include finding the impact of dietary habits on obesity in relation to gender differences among teenagers. The study will also focus on carrying out comparative analysis of the impact among teenagers from USA and rest of the world.

Significance of this study

This study is significant because it will not only help this age group to avoid obesity by focusing on their dietary plans, habits and behaviors but this will also help guide obese individuals to rethink their dietary habits and plans if required. The study will involve dietary habits of teenagers as independent variable and the prevalence of obesity will be checked as dependent variable against it.

Definitions of Key Terms:

Body Mass Index (BMI)

BMI is a measure used to determine obesity and overweight. It is measured by dividing total weight of a person by the square of his/he weight in meters. It is a measure that can indicate a weight category posed with health problems but it is not a diagnostic measure.

Overweight: Overweight is defined as the Body Mass Index between 85th and 95th percentile for children and teens belonging to the same age group and gender.

Obesity: Obesity is defined as the BMI of more than 95th percentile for all children and teens in the same age and sex group.

BMI in relation to obesity and overweight among teens and children is dealt very differently from that of adults. Adults are placed in different weight categories based on their BMI measures, while children are ranked based on BMI as a percentile of the same age group or same sex. BMI is age specific as well as sex specific among children and teens because of the changing body composition among them and also because it is different for male and female children and teens (Center for Disease Control and Prevention. 2015).


Center for Disease Control and Prevention. (2015). Defining Childhood Obesity. Retrieved from

Center for Disease Control and Prevention. (2015). Obesity prevalence maps. Retrieved from

Farajian, P., Panagiotakos, D. B., Risvas, G., Malisova, O., & Zampelas, A. (2014). Hierarchical analysis of dietary, lifestyle and family environment risk factors for childhood obesity: the GRECO study. European journal of clinical nutrition, 68(10), 1107-1112.

Garaulet, M., Ortega, F. B., Ruiz, J. R., Rey-Lopez, J. P., Beghin, L., Manios, Y., … & Moreno, L. A. (2011). Short sleep duration is associated with increased obesity markers in European adolescents: effect of physical activity and dietary habits. The HELENA study. International journal of obesity, 35(10), 1308-1317.

Janssen, I., Katzmarzyk, P. T., Boyce, W. F., Vereecken, C., Mulvihill, C., Roberts, C., & Pickett, W. (2005). Comparison of overweight and obesity prevalence in school‐aged youth from 34 countries and their relationships with physical activity and dietary patterns. Obesity reviews, 6(2), 123-132.

Rodrigo, C. P. (2013). Current mapping of obesity. Nutr Hosp, 28(Suppl 5), 21-31.